Contact-making voltmeter.



H. A. LAYGOGK.

' CONTACT MAKING VOLTMETER.

APPLICATION run 020.11, 1013.

1,119,616. Patented p90. 1, 1m

I I YTNEESES [NSZENTUH E i's A? man wax UNITED STATES PATENT OFFICE.

HARRY A LAYCOCK, OF SCHENECTADY, NEXV YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK CONTACT-MAKING VOLTMETER.

Specification of Letters Patent.

Patented Dec. 1, 1914.

Application filed December 11, 1913. Serial No. 306,067.

To all whom it may concern:

Be it known that I, HARRY A. LAYCOCK, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Contact- Making Voltmeters, of which the following is a specification.

My-invention relates to contact-making voltmeters, and more especially to an auxiliary switch provided in connection therewith as a protective device.

In the use of motor driven feeder regulators of the induction type, the operations of the motor are controlled by means of a special form of relay commonly known as a contact making voltmeter. Variations in voltage on the feeders cause the voltmeter to close oneor the other of two circuits and thereby rotate the motor drive, and hence the induction regulator, in one direction or the other, so as to bring the voltage back to the desired value. In case the energizing circuit of the voltmeter relay is broken, or in case thevoltage on th feeder is temporarily interrupted, the vol meter will so act as to cause the induction regulator to move to thatposition which would normally cause a maximum increase in voltage. When normal voltage is again supplied, it is instantly boosted by the regulator as much as'possible.v and before the voltmeter and motor can operate to move the regulator into the maxi mum lowering position and thereby reduce the voltage, considerable damage may result. v The object of my invention is to so construct a contact making voltmeter that in case of accident or temporary interruption of the voltage, the voltmeter will automatically operate to cause the regulator to move to the maximum lowering position and on the resumption of normal conditions, will again perform its usual functions. I accomplish this object by means of additional contacts operated by the same solenoid which operates the usual contacts.

In the accompanying drawing, the single figure is a diagrammatic view showing the construction of my voltmeter and the connections between it and an induction regulator. v

The feede s 1 are shown as connected to an induction regulator 2 of the usual construction which is operated by a motor 3. The movements of the motor are controlled by my contact making voltmeter 10 having a solenoid core 11 operated by either one or both of the coils 12 or 13. Energy for the coil 12 is obtained from the current transformer 14 connected to one of the feeders, while that for the coil 13 is obtained from the potential transformer 15 also connected to the feeders. The coil 13 operates the voltmeter by raising and lowering the core 1.1"

in response to variations of voltage on the feeders, while the coil 12 is used to oppose the coil .13 and compensate for line drop, means being provided to interrupt the circuit of either coil. At its upper end the core 11 is linked to a pivoted arm 16 to which is connected-a spring 17 so designed as to aid in balancing the weight of the core when the desired voltage is obtained on the feeders. On the pivoted arm 16 I provide contact points 18 which in their movements touch one or the other of the adjustable points 19 and 20 which are flexibly supported by springs 19 andZO. Power for driving the motor 3 is supplied from mains 30, and between the motor and the mains is inserted a reversing switch 31 operated by solenoids 32 and 33. The oscillating arm 16 is connected with one side of the source of supply 30, and the common terminal of the solenoids 32 and 33 is connected to the other side of said source. oted arm 16 in one direction or the other closes the appropriate circuit to operate the reversing switch 31. Evidently, the switch 31 could be omitted and'its work done by the arm 16, if desired. 7

It will be understood that the construction so far described is well known, and only shown to aid in understanding my inven tion.

Near the lower end-of the core 11 of my voltmeter I provide a spring contact arm 40 electrically connected with the contact 19. On this arm are contacts 41 which move he- Movement of the piv 1!; points 453 and 4:3. I

also prm'ii'lc an :1;

Hgi i 'llllQ si'llenpicl core 1]. 'lhr emu contact is. connected with the soir-noid i. whii: i ntact' l3 .1: conarc r'zi with the ontac-t point 2-0 and. with the sulcn id The parts of my voltmeter are so designed and :nljustrii that a. drop of -approximately Qf-{E-L in voltage will allow the core llto drop a tinsithe spri'ng a-rm 4-0 and thereby close a circuit between the contact points 41 and -13. It will he understood that this'circuit h energizing the solenoid 32 moves the reversing switch. so as toeaiise the motor 3 to b (h "cu in the a npropriatc direction to more the regn'hitor F3 to the maximum lowermg position. "In normal operation the arm ll floa s hr ion the contacts 19 and 20, but small rariaii-ns in voltage will cause the \"i lilncl' at to close a circuit between the 05-- rillal' I, a rm [(3 and either of the points 1!.)

2:3 and "1d thereby energize the solenoids 33-?- :-.n(l respectively, to more the regulator to the boosting and lowering positions, respectively. That is to say,;-a drop in voltage below normal allows the (ore 11 to drop slightly and bring the point 18- against the contact 19, thus energizing the solenoid Sin'iil:-'n:. an increase inroltage above normal raises the core 11 and closes the circuit of the solenoid, Energization of the sole- 35 noid 33 mores the switch 31 so to cause the router to turn the regulator toward the boosting position and rice-verse. Movcment ofthe arm 1!") sufficient to cause the contacts 13 to close one'or the other of the 4 circuits not snllieient to open the normally closed (arc-tritthrough the'contact points 4L.

and. hut whenarfahnormal variation in oltage'occm's the s rine; I-Q'E-Will bend and allow the core to drop -a Evidently; if; the springi lfi andthe contacts and 43 are emit-ted, an interruption of or excessive drop in voltage will 1 close the circuit to energize the solenoid 33 and thereby cause the regulator to be moredto the maxi- -rnuu1 lniosting posit-ion. By my construction I have, thereto 7 provided a device that will interchangei'he control circuit leading to one of the fixed contact points and thereby automatically more the regulator to amaximum lowering position whenever there is a fail ure of voltage on the feeders or whenever the connections hetwecn the feeder and the roltu'ieter are broken. This will prevent the voltmeter from causing the regulator to 50 more to the maximum boosting position as it would otherwise do without the provisions of. such an auxiliary switch. and will thereby prevent harn ful increases in -voltage on the rig screw ll for setseparates the" V tar-tor, l"

+mo'rement of said arm .nst the springA-O.

r feeders. Further, the operation of my a ux iliary switch is automatic, and upon a recstablislnncnt of normal conditions on the feeders the \oltn'iet-er will again operate to control the regulator in the desired manner without any attention from an operator.

I co nc'ci*."e that variations and modifications of the exact arrangement which I ha re herein shown might he made, and I therefore, do not wish to he lll'llltfiflll) this exact arrangement, but seek to cover in the apthe normal action of the contactor obtained by a decrease of voltage. 2. In a contact making voltmeter, contacton fixed contact points associated there.

with, circuits leading therefrom, and ineansr v normal] nnal'iectcd, rcsponsire to an' 211 14.;

normal variation in voltage to intm change the circuit leading to one of said points; f

3. In a cont-act making r'oltn'ieter, a con d comactpoints-associatcdtherewith, circuits leading therefrom, and mean normally nnalfecte ch responsive to an ah'n'or mal decrease in voltage to interchange the circuit lcadingto one of said points;

4. In a contact making voltmeter, a sole noid, a fioatin corc conncctedto a pivoted arm, contacts controlled'hy. ariiifand" uiica ns, normally una llected, rope tted by an abnormal movement of said cor e tofreferse the connections made by thesimultafneons In a contact making roltmeter, a con.- Y; Lactor respective to voltage "'itiliLClOllS, clo'S- ingalternate circui ts,' a.nd inegaixrs normally nnail ected, operative upon an abnormal-rariation of voltage in s edi' ectionto reverse the circuit connection simuhanednsly made by the cont-actor. I I

(3. In a contact malringw'oltmeter, acom tactor rcsponsire to voltage Variations, clos 7 ing alternate circuits, and means, normally. unall ected, operative upon aniahlnormal 'decrease of voltage to reverse the circuit conncction, simultaneously made by thef'coh tactor.

T. In a contact making. yoltmeter, a'izontactor arm pivoted intermediz'ite its'lengtlg. contact points cooperating withi sai d arm near one end thereo'f, and means, normally unaffected, responsive to an abnormal moement of the other end of said arm to interchange the circuit connection to one of said' contact points.

8. In a eonta ct making voltmeter, a .con- In witness whereof, I have hereunto set v teeter ngrmally floating between relatively my hslnd this 10th day of December, 1913.

fixed Contact points, a solenoid for support- HARRY A LAYGOCK ing said eentactor and a contact spring op- 5 stated by said contactor for interchanging Witnesses:

the circuit connection to one of said points BENJAMIN B. HULL, when the solenoid is denergized. HELEN ORFORD.

flop-fies 0i flak patent may be obtained for'flv'e cents each, by addressing the Commissioner of Patents, 4 Washington, D; O. 

